Differential immunocytochemical localization of tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA) in breast cancer.

The presence of tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA) in serial sections of 44 breast carcinomas, one case of neurofibrosarcoma, and one case of fibroadenoma was demonstrated by immunocytochemistry using the indirect peroxidase technique. The neurofibrosarcoma was negative for TPA and CEA. All 44 specimens of breast cancer were positive for TPA and/or CEA. In 18 cases the staining was strongly positive for TPA and CEA. The overall concordance of staining was 43%. TPA was more prominent than CEA in 52% of the tumors while CEA was more prominent in 7%. This is in relative agreement with the values for TPA and CEA in serum from patients with breast cancer, where TPA was higher than CEA in 41% and CEA higher than TPA in 9%. The finding of a difference between and within tumors indicated that TPA and CEA may be synthesized during partly different phases of the proliferative cycle. Assay of TPA and CEA in cytological specimens and in serum should be of clinical interest.